package learn.spring.api.utils;

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;
import java.util.UUID;

/***
 * 生成client_id、client_secret
 */
public class ClientKeyUtils {

  //生成 client_secret 密钥
  private final static String[] chars = new String[]{"a", "b", "c", "d", "e", "f",
      "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "r", "s",
      "t", "u", "v", "w", "x", "y", "z", "0", "1", "2", "3", "4", "5",
      "6", "7", "8", "9", "A", "B", "C", "D", "E", "F", "G", "H", "I",
      "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V",
      "W", "X", "Y", "Z"};

  private static String getAppId() {
    StringBuffer shortBuffer = new StringBuffer();
    String uuid = UUID.randomUUID().toString().replace("-", "");
    for (int i = 0; i < 8; i++) {
      String str = uuid.substring(i * 4, i * 4 + 4);
      int x = Integer.parseInt(str, 16);
      shortBuffer.append(chars[x % 0x3E]);
    }
    return shortBuffer.toString();

  }

  private static String getAppSecret(String appId, String serverName) {
    try {
      String[] array = new String[]{appId, serverName};
      StringBuffer sb = new StringBuffer();
      // 字符串排序
      Arrays.sort(array);
      for (int i = 0; i < array.length; i++) {
        sb.append(array[i]);
      }
      String str = sb.toString();
      MessageDigest md = MessageDigest.getInstance("SHA-1");
      md.update(str.getBytes());
      byte[] digest = md.digest();

      StringBuffer hexstr = new StringBuffer();
      String shaHex = "";
      for (int i = 0; i < digest.length; i++) {
        shaHex = Integer.toHexString(digest[i] & 0xFF);
        if (shaHex.length() < 2) {
          hexstr.append(0);
        }
        hexstr.append(shaHex);
      }
      return hexstr.toString();
    } catch (NoSuchAlgorithmException e) {
      e.printStackTrace();
      throw new RuntimeException();
    }
  }
}
